Many non-viscous liquid products are desirably packaged in pull tab-type containers for easy opening and ready discharge of contents from the container. A good number of such products, however, are intended for discharge from the container into relatively small and confined receptacle inlets; this being particularly well illustrated in the instances where automotive and fuel or lubricant additive materials are packaged in containers intended to be discharged into the openings of gasoline tanks or other storage units. In such cases, the demands of ultimate convenience and efficiency militate against the use of funnels and the like flow-controlling or -directing auxiliaries.
The known easy opening, pull tab-style containers (or, more precisely, the end covers for same) are not well adapted upon being opened to have automatically and effectively thereupon an integral and efficient pour guide resulting from the pulled-up tab with which good and accurate flow control can be achieved for and upon the discharge during entire emptying of the container's contents.
This is despite the fact that most pull tabs for easy opening container ends are capable, regardless of their normal operating orientation, of being pivoted, rocked or otherwise positioned into an attitude more or less perpendicular to the end. This alone, however, is not adequate for the upraised tab to effectively function as a pour guide. For such desideratum, the pour orifice must be sufficiently restricted so that the fluid discharge, especially from a full container, can be controllably poured down the extended open tab which, at the same time, must be positioned sufficiently close to the container wall so that the tab continues its function as a pour guide until the container is effectively empty.
The indicated criteria are not met by containers wherein the operating attitude of the pull tab is in a non-interfering, folded back position. Neither is it fulfilled by containers wherein the upraised pull tab creates too large an opening tending to preclude exercise of effective control over fluid being poured from a full container and/or to lose any possibility or means of control with a partially (say, 1/4 to 1/3) full container. The same applies to containers wherein the opened, upraised tab is positioned too closely to the center of the end panel or where precise partial opening to avoid such an inefficient end location of the upstanding tab would require, on each occasion of container opening, the not automatically and certainly predeterminable final efficient pour guide disposition of the tab but an unreliable and not inherently or easily determinably exercise of unpredictable judgement and experimentation to possibly change the obtention of a good-enough pour guide manipulation for each single operating occassion.
Obviously, the drawbacks and inadequacies of known easy open containers for utilization in the mentioned capacity and for the indicated purpose lead overwhelmingly and literally invariably to disadvantageous, vexatious and usually unavoidably wasteful and undesirable consequences.